There are so many forums here, that I am not sure if this is the right place to ask questions about the tutorial, Arduino as ISP and Arduino Bootloaders: (https://www.arduino.cc/en/tutorial/arduinoISP "Last revision: 2018/01/20 by SM").
My question is kind of related to "Bootloader Issues", so I hope I am in the right place. (If not, feel free to move this post, but leave a bread-crumb here to let me know where to look for the answer.)
I am confused as to whether an Arduino UNO R3, used as an ISP programmer, requires the 10 µF capacitor or not (between the programmer UNO's RESET and GROUND pins, to prevent the auto-reset problem).
There are two pictures in the tutorial that show connections for a UNO programming another UNO, and a UNO programming a NANO. Neither of these pictures show a capacitor on the UNO (used as the programmer). The pictures do show the extra ISP connector for the ATmega16U2, so I am assuming that these pictures show the UNO Rev 3 board as the ISP programmer.
The next picture shows a MEGA board used to program a UNO, and shows the 10 µF capacitor between the MEGA's RESET and GROUND pins. The comment underneath the picture says (emphasis added by me):
This type of board needs a 10µF electrolytic capacitor...
implying that this is a new and different requirement, than the connections shown in the previous two examples.
BUT THEN, the next paragraph says (emphasis added by me):
The 10µF electrolytic capacitor ... is needed only for the boards that have an interface between the microcontroller and the computer's USB, like Mega, UNO, Mini, Nano.
I know that the UNO design has changed over time and that earlier ones had the FTDI USB interface chip (and some UNO clones had or still have the CH340 or similar chip), and that these boards DO need the capacitor. I also know that the UNO Rev 3 uses the ATmega16U2 as the USB interface, but I am not sure if these boards need the capacitor or not.
So, does a UNO Rev 3 (with the ATmega16U2) need the 10 µF capacitor or not (when used as an ISP programmer)?
Could "SM" (or someone) please update the tutorial to remove this ambiguity, or explicitly state which UNO boards (if any) need the capacitor and which (if any) do not?
Thanks and best regards,
DuinoSoar